Conventionally, in relation to turning, there is proposed a numerical control device that includes a cutting tool feeding mechanism for causing a cutting tool to perform a feeding operation with respect to a workpiece, and a control mechanism for controlling a cutting tool feed-drive motor while applying low frequency vibration to the cutting tool (see Patent Literatures 1 to 3). In this numerical control device, the control mechanism includes: an operation unit for performing various kinds of setting; a vibration cutting information storing unit that stores a table prepared in advance at least about the advancing amount, retreating amount, advancing speed, and retreating speed of the cutting tool feeding mechanism, in accordance with a mechanical characteristic, such as a feeding axis inertia or a motor characteristic, where the table is stored as data that enables the cutting tool to operate at a low frequency of 25 Hz or more to perform a feeding operation in a synchronizing state, in accordance with a revolution number of the workpiece or a feeding amount of the cutting tool per rotation of the cutting tool, which has been set by the operation unit; and a motor control unit for controlling the cutting tool feed-drive motor, based on the data stored in the vibration cutting information storing unit. With this arrangement, the low frequency vibration is generated by repeating the advancing and retreating operations along an interpolation path.